Investigation into the role of autophagy protease ATG4A in normal and impaired erythropoiesis

自噬蛋白酶 ATG4A 在正常和受损红细胞生成中的作用研究

• 批准号: 10558651
• 负责人: Massiel Chavez Stolla
• 金额: $ 14.8万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10558651
• 关键词: Acetylcysteine; Antioxidants; Autophagocytosis; Autophagosome; BCL-2 Protein; BCL2/Adenovirus E1B 19kd Interacting Protein 3-Like; Biology; Cell Differentiation process; Degradation Pathway; Development; Disease; Dysmyelopoietic Syndromes; Erythroblasts; Erythrocytes; Erythroid; Erythroid Cells; Erythropoiesis; Ferritin; Genes; Hematological Disease; Hematology; Hematopoietic; Heme; Hemoglobin; Human; Impairment; International; Investigation; Iron; K-Series Research Career Programs; Knowledge; Laboratories; Mammalian Cell; Measures; Mediating; Mentorship; Metabolism; Mitochondria; Organelles; Oxidative Stress; Patients; Peptide Hydrolases; Preparation; Production; Proteins; Reactive Inhibition; Reactive Oxygen Species; Regulation; Reporter; Research Personnel; Role; Sideroblast; TFRC gene; Therapeutic Intervention; Tissues; Training; Universities; Washington; erythroid differentiation; experimental study; human model; improved; in vivo; induced pluripotent stem cell; inhibition of autophagy; macromolecule; metabolomics; mitochondrial dysfunction; model organism; mouse model; new therapeutic target; oxidation; progenitor; receptor; recruit; selective expression; stem cell model

PROJECT SUMMARY/ ABSTRACT Autophagy is a self-degradation pathway that has tissue-specific functions in erythropoiesis. During erythroid differentiation, autophagy facilitates the degradation of macromolecules and the programmed clearance of mitochondria. The long-term objective of this proposal is to determine how autophagy contributes to normal and impaired erythropoiesis. Patients with Myelodysplastic syndromes (MDS) often have impaired erythropoiesis and mitochondrial dysfunction. A subset of MDS, MDS with ring sideroblasts (RS), contain the aberrant accumulation of iron-laden mitochondria in erythroblasts suggesting that autophagy may be dysregulated in hematopoietic disorders and impair erythroid differentiation. While essential autophagy genes are known to contribute to autophagy in erythropoiesis, little is known about the tissue-specific regulation of autophagy during human erythroid differentiation. We have identified the selective expression of the autophagy protease ATG4A in the erythroid lineage. We have evaluated the contribution of ATG4A in an ex vivo model of human erythroid differentiation. Early in differentiation, ATG4A promotes the expansion and colony formation of erythroid progenitors. Late in differentiation, ATG4A promotes terminal maturation, enucleation, and mitochondrial clearance. Since ATG4 proteases are regulated by reactive oxygen species, the function of ATG4A in erythropoiesis may be sensitive to oxidative stress. Based on our preliminary results, we hypothesize that ATG4A mediates autophagy during early and late erythropoiesis and is dysregulated by oxidative stress. In aim 1, we will identify the role of ATG4A-dependent autophagy in early erythropoiesis. In aim 2, we will determine the mechanism of ATG4A-dependent mitochondrial clearance. In aim 3, we will examine the regulation of mitochondrial clearance in human models of MDS-RS. The experiments outlined in this proposal will be conducted under the mentorship of Dr. Sergei Doulatov, an expert in the development and use of human iPSC models to study erythroid disorders, and co-mentorship of Dr. Janis Abkowitz, Chair of the Division of Hematology at the University of Washington and international expert in MDS and erythroid biology. This career development award will support my training to become an independent investigator studying the contribution of autophagy to normal and dysfunctional erythropoiesis.

项目概要/摘要 自噬是一种自我降解途径，在红细胞生成中具有组织特异性功能。红系期间 分化、自噬促进大分子的降解和程序性清除 线粒体。该提案的长期目标是确定自噬如何促进正常和 红细胞生成受损。骨髓增生异常综合征 (MDS) 患者的红细胞生成功能通常受损 和线粒体功能障碍。 MDS 的一个子集，具有环形铁粒幼细胞 (RS) 的 MDS，包含异常 成红细胞中铁负载线粒体的积累表明自噬可能失调 造血障碍并损害红细胞分化。虽然已知重要的自噬基因 有助于红细胞生成过程中的自噬，但人们对红细胞生成过程中自噬的组织特异性调节知之甚少。 人类红细胞分化。我们已经鉴定出自噬蛋白酶 ATG4A 的选择性表达 在红系谱系中。我们评估了 ATG4A 在人红系离体模型中的贡献 差异化。在分化早期，ATG4A 促进红系细胞的扩张和集落形成 祖先。在分化后期，ATG4A 促进终末成熟、去核和线粒体 清除。由于 ATG4 蛋白酶受活性氧调节，因此 ATG4A 的功能 红细胞生成可能对氧化应激敏感。根据我们的初步结果，我们假设 ATG4A 在早期和晚期红细胞生成过程中介导自噬，并因氧化应激而失调。瞄准目标 1，我们将确定 ATG4A 依赖性自噬在早期红细胞生成中的作用。在目标 2 中，我们将确定 ATG4A 依赖性线粒体清除机制。在目标 3 中，我们将审查 MDS-RS 人类模型中的线粒体清除率。本提案中概述的实验将是 在人类 iPSC 开发和使用专家 Sergei Doulatov 博士的指导下进行 研究红细胞疾病的模型，以及该部门主席 Janis Abkowitz 博士的共同指导 华盛顿大学血液学教授，MDS 和红细胞生物学国际专家。这个职业 发展奖将支持我接受培训，成为一名独立调查员，研究以下方面的贡献 自噬对正常和功能失调的红细胞生成。